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Flashcards in Brainstem Deck (55):
1

name the 3 main components of the brainstem

  • midbrain
  • pons
  • medulla
  • the brainstem transitions to the spinal cord after it exits through the foramen magnum

2

name 7 landmarks of the midbrain

  1. quadrigeminal plate (tectum)
  2. cerebral peduncles
  3. cerebral aqueduct
  4. red nucleus
  5. substantia nigra
  6. CN III
  7. CN IV

3

what are the two structures that sit on the quadrigeminal plate, and what are their basic functions?

  1. superior colliculus - preliminary visual processing
  2. inferior colliculus - auditory processing

4

describe the cerebral peduncles

  • aka crus cerebri
  • relay for cortico-spinal, cortico-pontine, and cortico-bulbar tracts*
  • *tract = collection of axons

5

describe the cerebral aqueduct

  • aka mesencephalic aqueduct; aqueduct of Sylvius
  • contains CSF
  • connects 3rd and 4th ventricles

6

describe the red nucleus

  • involved in motor coordination
  • extrapyramidal system
  • nucleus = collection of cell bodies in the central nervous system

7

describe substania nigra

  • involved in movement and reward (addiction)
  • extrapyramidal system
  • parkinson's disease

8

describe CN III

  • oculomotor nerve
  • eye movement
  • pupil constriction and lens accommodation
  • pupillary light reflex

9

describe CN IV

  • trochlear nerve
  • clinically test it looking in and down

10

name the 9 landmarks of the pons

  • pons proper
  • middle cerebellar peduncle
  • fourth ventricle
  • basilar artery
  • CN V
  • CN VI
  • CN VII
  • CN VIII

11

describe the pons proper

  • corticospinal tract
  • cerebellar tracts

12

describe the middle cerebellar peduncle

  • largest of the 3 cerebellar peduncles
  • contains fibers that arise from the contralateral pontine nuclei and end in the cerebellum

13

describe the 4th ventricle

  • contains CSF
  • communicates with subarachnoid space via median and lateral apertures
  • connects 3rd and 4th ventricles

14

describe the basilar artery

  • formed by vertebral arteries
  • gives rise to: AICA, pontine aa., superior cerebellar a., and PCA

15

describe CN V

  • trigeminal n.
  • muscles of mastication: jaw jerk reflex
  • sensation from head
  • corneal reflex

16

describe CN VI

  • abducens n.
  • lateral eye movements

17

describe CN VII

  • facial n.
  • muscles of facial expression
  • corneal reflex
  • "closes eye, makes you cry, tastes pie, and innervates all glands in the head except the one it's inside"

18

describe CN VIII

  • vestibulocochlear n.
  • hearing and balance

19

name the 9 landmarks of the medulla

  • 4th ventricle
  • pyramid
  • olive
  • vertebral arteries
  • CN VIII
  • CN IX
  • CN X
  • CN XI
  • CN XII

20

describe the pyramid

  • decussation of corticospinal tract

21

describe the olive

  • CN XII exits between the pyramid and olive
  • fibers course to the cerebellum

22

describe vertebral arteries

  • PICA
  • forms basilar a.

23

describe CN VIII

  • vestibulocochlear n.
  • vestibular nucleus descends to medulla

24

describe CN IX

  • glossopharyngeal nerve
  • gag reflex
  • baroreceptor reflex

25

describe CN X

  • vagus n.
  • palatal mm. (symmetrical palatal elevation)
  • pharyngeal mm. (swallowing)
  • laryngeal mm. (swallowing)

26

describe CN XII

  • hypoglossal n.
  • tongue deviation to side of lesion ("lick your wounds")

27

describe the 1st, 2nd, 3rd, 4th, and 6th branchial arches

  • 1st: muscles of mastication (CN V)
  • 2nd: muscles of facial expression (CN VII)
  • 3rd: stylopharyngeus (CN IX)
    4th and 6th: palatal, pharyngeal, and laryngeal mm. (CN X)

28

what are branchial motor nuclei?

specialized branchail arches form skeletal muscle in the head. therefore, motor nuclei to supply innervation is unique to brainstem

29

what makes up the the otic placode?

  • auditory system (hearing)
  • vestibular system (balance)

30

describe hearing and balance nuclei

special senses for hearing (cochlear apparatus) and balance (semicircular canals)require sensory nuclei unique to the pons and medulla

31

describe organization of sensory and motor nuclei

no matter what additional nuclei are added, the sensory nuclei are lateral to sulcus limitans and motor nuclei are medial

32

T or F:

brainstem nuclei of specific modalities are in different vertical columns

false:

they will be in the same vertical columns

33

keeping in mind the vertical arrangement of brainstem nuclei, which CN nuclei are somatic motor?

  • CN III
  • CN IV
  • CN VI
  • CN XII

34

keeping in mind the vertical arrangement of brainstem nuclei, which CN nuclei are branchial motor?

  • CN V
  • CN VII
  • CN IX
  • CN X

35

keeping in mind the vertical arrangement of brainstem nuclei, which CN nuclei are visceral motor?

  • CN III
  • CN VII
  • CN IX
    CN X

36

describe the oculomotor nucleus

  • somatic motor
  • innervates levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, inferior oblique mm

37

what would happen to eye movement if the oculomotor nucleus is damaged?

  • ptosis - eyelid droops
  • eye deviates to down and out position

38

describe the edinger-westphal nucleus

  • part of midbrain
  • visceral motor parasympathetic (CN III) to pupillary constrictor and ciliary muscles
  • axon travels from E-W nucleus, synapses on ciliary ganglion, second order neuron reaches targets
  • causes pupils to constrict

39

what happens if the edinger-westphal nucleus is damaged?

  • remember that the E-W nucleus is responsible for constriction of pupil
  • damage causes mydriasis (eye dilates) due to the unopposed action of the dilator pupillae muscle (sympathetic)

40

how do you test the trochlear nerve?

well, it's complicated

41

name the 8 structures involved in the pupillary light reflex

  • optic nerve
  • optic chiasma
  • olivary pretectal nucleus
  • Edinger-Westphal nucleus (VM CN III)
  • CN III
  • ciliary ganglion
  • pupil constriction
  • consensual reflex (both sides react)

42

what are the 4 nuclei in the pons?

  • trigeminal motor nucleus
  • abducens nucleus
  • superior salivary nucleus
  • facial motor nucleus

43

describe the trigeminal motor nucleus

  • branchial motor to muscles of mastication

44

describe the corneal reflex

  • consensual reflex
  • sensory: CN V1 to spinal trigeminal nucleus
  • motor: facial nucleus out to the temporal branch of CN VII
  • touch cornea and result should cause both eyes to blink

45

describe the abducens nucleus

  • origin of abducens n. (CN VI)
  • innervates lateral rectus m. - abduction of the eye

46

describe the superior salivary nucleus

  • visceral motor (parasympathetic) to lacrimal, nasopalatine, submandibular, and sublingual salivary glands (all glands EXCEPT parotid)

47

describe the facial motor nucleus

  • innervates facial expression mm.
  • located in rostral pons
  • wraps around abducens nucleus and then exits
  • closes eye, makes you cry, tastes pie, and innervates all the glands except the one it's inside (parotid)

48

which 4 nuclei are in the medulla?

  • hypoglossal nucleus (CN XII)
  • dorsal vagal nucleus
  • inferior salivatory nucleus
  • nucleus ambiguus

49

describe the hypoglossal nucleus 

  • CN XII
  • somatic motor to tongue mm.
  • gives rise to axon that courses out between pyramid and olive 

50

what happens if there is damage to the hypoglossal nucleus or hypoglossal nerve?

  • "lick your wound" - tongue will deviate towards the side of the lesion
  • genioglossal m. won't work

51

describe the dorsal vagal nucleus (aka dorsal motor nucleus)

  • CN X
  • visceral motor (parasympathetic) to thoracoabdominal organs:
    heart
    trachea, bronchial tree
    GI tract (esophagus, fore- and midgut)
    accessory GI glands (liver, gallbladder, pancreas)

52

describe the salivatory nucleus

  • CN IX
  • visceral motor (parasympathetic) to parotid gland

53

describe what a nucleus, axon, and neuron is

  • nucleus - collection of cell bodies
  • axon - collection of nerves
  • neuron - single cell body and axon

54

describe the nucleus ambiguus 

  • CN IX and CN X
  • branchial motor to palatal, pharyngeal, and laryngeal mm.

55

describe the gag reflex

  • sensory (CN IX) - touch the back of the throat
  • motor (CN X via nucleus ambiguus) - pharyngeal and palatal muscles contract